Payments for Law Firms: IOLTA Rules, LawPay, and What Stripe and Square Actually Cost You

The short version: law firms do not have a payments problem, they have a trust-accounting problem that looks like a payments problem. Client funds and earned fees must never touch the same ledger line — ABA Model Rule 1.15 and every state version of it say so — and most generic processors were built by people who have never heard of IOLTA. That is why legal-specific processors like LawPay and Clio Payments exist, and why putting Stripe or Square on a law firm site without a trust-accounting plan is how bar complaints start. Rates checked October 2026. Also see Law Firms, AI for Law Firms, and Tech for Law Firms.

The one rule that changes everything: trust vs. operating

Every dollar a law firm touches is either the client's money (retainers, settlement funds — held in the IOLTA/trust account) or the firm's money (earned fees — the operating account). Commingling is the fastest route to discipline in legal ethics. The payments consequence: processing fees may never be deducted from trust funds. When a client pays a $5,000 retainer by card and the processor takes its cut, that cut must come out of the operating account — which means the full $5,000 must still land in trust.

Legal-specific processors handle this split natively: the fee is drawn from operating while the gross goes to trust. Generic processors do not — which is why firms using Stripe or Square for retainers end up doing manual true-ups every month, and why a missed true-up is an ethics problem, not a bookkeeping annoyance. Second consequence: most states restrict or prohibit passing card surcharges to clients, and several bar opinions treat fee pass-through on trust deposits as a per se violation. If your "solution" is a 3% surcharge on retainers, check your state's opinion before you check your processor's pricing page.

The fee table: what each processor actually charges a law firm

On a $5,000 retainer paid online, the math (rates checked October 2026):

• LawPay (about $25/month base; published card-present around 1.95% + $0.20, card-not-present higher): roughly $100–$175 on the retainer, with the fee correctly split to the operating account. The premium buys IOLTA-correct settlement and bar-association endorsements in all 50 states.
• Clio Payments (around 2.8% per transaction, no separate monthly fee in most plans): about $140 on the retainer, with trust/operating separation built into Clio's ledger. Best value if you already live in Clio.
• Stripe (2.9% + $0.30 online): $145.30 — but no trust/operating split, so the monthly true-up is on you, and your state's bar may have an opinion about where the fee lands.
• Square (2.9% + $0.30 online; 2.6% + $0.15 in-person): $145.30 online, ~$130.15 in person — same trust-accounting gap as Stripe, plus Square's aggregated-risk model has a documented history of freezing accounts on unusual volume spikes, which is a terrible trait in a business that receives $50,000 settlement checks.
• Chase Payment Solutions / Fiserv / Global Payments / Worldpay / Adyen: quote-based, enterprise-led, zero legal-specific trust-accounting guidance on their SMB pages. You will pay for a payments consultant to replicate what LawPay does out of the box.

Notice what the table really says: the fee differences are tens of dollars. The trust-accounting automation is the product — and the generic processors do not sell it at any price.

The workflow checklist the big processors fail

Run any processor against this list before you sign:

• Trust/operating split at settlement — gross to trust, fee to operating, automatically. LawPay and Clio Payments: yes. Stripe/Square: manual.
• Retainer replenishment billing — "your trust balance hit $1,000, please replenish $4,000" with a payment link. Legal processors build this in; generic ones make you build it in Zapier.
• eCheck/ACH for large payments — ACH at 0.8% capped at $5 (Stripe's rate) beats 2.9% on a $25,000 settlement-adjacent payment by hundreds of dollars. Your processor should offer it natively.
• Payment plans that respect the ledger — monthly installments against an operating-account receivable, never against trust.
• Surcharge rules by state — the processor will not tell you your bar prohibits it. Finix's public docs are a useful neutral reference on how surcharging and dual-pricing programs actually work mechanically, so you can compare against what your state allows.
• Three-way reconciliation support — trust ledger, bank statement, and client ledgers must tie. If the processor cannot export per-client settlement detail, your bookkeeper will hate you.

The honest verdict on each processor

LawPay: the default right answer for most firms. You pay a monthly base and a rate premium for IOLTA-correct settlement and the bar endorsements that make your malpractice carrier happy. Worth it the first time a trust-account question comes up.

Clio Payments: the right answer if you already run Clio — the trust ledger and the payments live in one place, which is where the reconciliation magic happens.

Stripe: fine for operating-account payments (earned fees, consultation fees) with careful configuration; a liability for trust deposits unless you build the true-up discipline and your state allows the arrangement. Powerful API, zero legal awareness.

Square: the worst fit of the majors for law firms — aggregated risk holds plus no trust tooling. Fine for selling firm merch; not for retainers.

The enterprise five (Chase, Fiserv, Global Payments, Worldpay, Adyen): built for volume, not for ethics rules. None publishes legal-specific guidance; all will happily sell you a generic merchant account and wish you luck with your bar.

If retainer billing and payment plans are eating your month, ClaroPro handles the voice-driven side — speak the invoice, send the payment link — while the legal processor handles the trust-correct settlement underneath.

Retainer replenishment and payment plans: the two workflows that decide cash flow

Two workflows separate firms that collect from firms that chase. Retainer replenishment: the trust balance hits the floor you set ($1,500, say), and the client automatically gets the replenishment invoice with a payment link — no partner remembering, no awkward call. LawPay and Clio Payments both build this; the firms that turn it on stop having "the retainer ran dry mid-case" conversations. Payment plans: the $15,000 family-law matter becomes six monthly operating-account charges, invoiced automatically, with the engagement letter's payment terms attached. The plan is against the operating receivable — never against trust — and the dunning handles the expired card before you do.

The cash-flow math: a firm with 40 active matters on payment plans at $1,000/month average has $40,000 of predictable monthly inflow that does not depend on anyone remembering to bill. That predictability is what lets a small firm hire the paralegal before the work arrives instead of after.

FAQ

Can a law firm use Stripe for retainers? Technically yes, ethically it depends on your state — the fee must not come out of trust funds, which Stripe will not split for you. Most firms that try it end up on LawPay within a year.

What is IOLTA-compliant processing? Settlement that keeps client funds whole in the trust account while processing fees draw from the operating account, with per-client reporting that supports three-way reconciliation.

Can I surcharge clients for card fees? Many states prohibit or restrict it, and bar opinions are stricter than state law. Check your jurisdiction's ethics opinions before your processor's pricing page.

What about ACH for large payments? Usually the cheapest option — around 0.8% capped at a few dollars beats 2.9% on anything over a few thousand. Offer it on every invoice over $5,000.

How do I automate retainer replenishment? Set the floor in LawPay or Clio Payments; the system invoices the client automatically when the trust balance hits it. Review the floor quarterly against matter burn rates.

Are payment plans ethical? Yes — against the operating account, with written terms in the engagement letter. The ethics issue is only ever about trust funds; keep plans off trust and you are fine.

The move: 1) put retainers and trust-adjacent money on LawPay or Clio Payments this month. 2) Offer ACH on every invoice over $5,000. 3) Check your state's surcharge opinion before you "optimize" anything. The fees are the smallest part of this decision; the trust accounting is the whole decision. For the software underneath it all, read Tech for Law Firms — and if your intake is still a voicemail, start with Finix-grade payment links on every invoice, not a new processor.